Search results for "Crystalline Silicon"
showing 10 items of 74 documents
3D modeling of doping from the atmosphere in floating zone silicon crystal growth
2017
Abstract Three-dimensional numerical simulations of the inert gas flow, melt flow and dopant transport in both phases are carried out for silicon single crystal growth using the floating zone method. The mathematical model allows to predict the cooling heat flux density at silicon surfaces and realistically describes the dopant transport in case of doping from the atmosphere. A very good agreement with experiment is obtained for the radial resistivity variation profiles by taking into account the temperature dependence of chemical reaction processes at the free surface.
Evaluation of the Performance of Published Point Defect Parameter Sets in Cone and Body Phase of a 300 mm Czochralski Silicon Crystal
2021
Prediction and adjustment of point defect (vacancies and self-interstitials) distribution in silicon crystals is of utmost importance for microelectronic applications. The simulation of growth processes is widely applied for process development and quite a few different sets of point defect parameters have been proposed. In this paper the transient temperature, thermal stress and point defect distributions are simulated for 300 mm Czochralski growth of the whole crystal including cone and cylindrical growth phases. Simulations with 12 different published point defect parameter sets are compared to the experimentally measured interstitial–vacancy boundary. The results are evaluated for stand…
Residual crystalline silicon phase in silicon-rich-oxide films subjected to high temperature annealing
2002
Structural properties of silicon rich oxide films (SRO) have been investigated by means of micro-Raman spectroscopy and transmission electron microscopy (TEM). The layers were deposited by plasma enhanced chemical vapor deposition using different SiH4/O2 gas mixtures. The Raman spectra of the as-deposited SRO films are dominated by a broad band in the region 400-500 cm-1 typical of a highly disordered silicon network. After annealing at temperatures above 1000°C in N2, the formation of silicon nanocrystals is observed both in the Raman spectra and in the TEM images. However, most of the precipitated silicon does not crystallize and assumes an amorphous microstructure. © 2002 The Electrochem…
One-step formation of nanostructures on silicon surfaces using pure hydrogen-radical-initiated reactions
2013
One-step formation of silicon nanowires, sheets, and texture surface on a silicon substrate has been achieved using hydrogen-radical etching reactions. Metallic tungsten and for comparison purposes a tungsten hot wire, were used as catalysts for the hydrogen-molecular cracking. It was shown that a variety of surface structures on silicon such as inverted pyramid texture, V-groove texture, dense silicon nanowire growth over texture, and nanosheet structure can be obtained by controlling the process conditions. The obtained results suggested that the formation of nanotungsten silicide particle is an essential prerequisite to obtain these structures. The particles work as an etching mask again…
Improved Temperature Coefficient Modeling through the Recombination Parameter $\gamma$
2020
This study presents an injection dependent numerical model relating Shocldey-Read-Hall defect parameters in crystalline silicon with the recombination parameter $\gamma$ . We demonstrate how the model can be used to predict $\gamma$ for various single level defects. Additionally, we show that $\gamma$ can be significantly influenced by the injection level, in contrast to what is commonly assumed. The injection dependence is found to correlate with the temperature sensitivity of the Shocldey-Read-Hall lifetime. Finally, we demonstrate that the model can be used to predict the temperature coefficient of the open circuit voltage without the use of a temperature dependent measurement, enabling …
Scanning electron microscopy analysis of defect clusters in multicrystalline solar grade silicon solar cells
2014
Solar cells from an identical commercial manufacturing unit have been investigated by electroluminescence to first detect the defect clusters. A further analysis has been done by scanning electron microscopy in secondary electron imaging mode to understand the propagation mechanism of defects. It appears that defect cluster boundaries can be very sharp or spread in the bulk with little apparent effect on the overall cell efficiency. And it is shown that grain boundaries act clearly as arrests to further propagation of these defects.
Modeling and parameter identification of crystalline silicon photovoltaic devices
2011
In this paper the physical correctness of the standard single-exponential (one-diode) model of crystalline-Si photovoltaic devices is examined. In particular, we focus on the shunt current. I-V curves of in situ illuminated polycrystalline-Si photovoltaic modules are measured, and based on these measurements, we extract the shunt current. There is a certain voltage range in which the shunt current shows an Ohmic-like behavior, but the value of the resistance varies with irradiance and the quality of illumination. In addition, the Ohmic behavior takes place at voltages well below the maximum-power point (MPP). At higher voltages, the shunt current drops to negligible values. We conclude that…
Memory effects in MOS capacitors with silicon rich oxide insulators
2000
ABSTRACTTo form crystalline Si dots embedded in SiO2, we have deposited thin films of silicon rich oxide (SRO) by plasma-enhanced chemical vapor deposition of SiH4 and O2. Then the materials wereannealed in N2 ambient at temperatures between 950 and 1100 °C. Under such processing, the supersaturation of Si in the amorphous SRO film produces the formation of crystalline Si dots embedded in SiO2. The narrow dot size distributions, analyzed by transmission electron microscopy, are characterized by average grain radii and standard deviations down to about 1 nm. The memory function of such structures has been investigated in metal-oxidesemiconductor (MOS) capacitors with a SRO film sandwiched be…
Initial light-induced degradation study of multicrystalline modules made from silicon material processed through different manufacturing routes
2012
The paper presents results of initial lightinduced degradation (LID) of multicrystalline silicon photovoltaic (PV) modules made of crystalline silicon from different manufacturing processes. The modules were installed within the Sunbelt, in Hyderabad, India. Current-voltage (I–V) characteristics are measured and infra-red (IR) images of the modules are taken at regular intervals. A relationship of the IV degradation with the IR images is discussed. Results from laboratory LID tests at room temperature are performed parallel to the outdoor degradation of PV modules. It was found that the total LID, measured on the module level, after the initial 40 hours is similar for both materials resulti…
Assessment of a New Analytical Expression for the Maximum-Power Point Voltage with Series Resistance
2021
This work compares a recently developed analytical expression for the maximum-power point voltage with experimental data, to test its usability for crystalline silicon solar cells. The experimental data covers measurements from 18 multicrystalline silicon solar cells with different bulk resistivities and cell architectures. We show that the expression is able to predict the maximum power obtainable by the measured cells with relative discrepancies below 1%. Additionally, we compare the accuracy of this new expression with two already existing models.